A high field multinuclear NMR spectrometer is needed to support new and ongoing projects at Marquette University and the greater Milwaukee area. The proposed instrument will support and extend existing NIH and other funded projects for 6 major users and 4 minor users from 3 institutions. The major user group is funded by 8 NIH grants, and minor users are funded from various sources. The major users are involved in projects directed to problems in biochemistry that make central use of NMR, and the minor users have projects that rely heavily on NMR in a supporting role. A key feature required of the spectrometer will be the high sensitivity and resolution available at 600 MHz, in order to study protein-ligand interactions. The NMR facility will offer a wide variety of probe choices, including MicroFlow and BB, thereby satisfying a regional need unmet by other facilities. Projects include: (1) Probing protein-ligand interactions in chemical proteomics: NMR methods development and application (Sem), (2) Complementary use of NMR and Raman studies to probe ligand binding to cytochrome P450cam (Kincaid), (3) Role of Su e information of the Fi-Fo ATP synthase dimeric complex: structural and binding studies (Stuart), (4) Mechanism of flagellar radial spoke: ligand binding and structural studies of radial spoke protein 2 (RSP2) (Yang), (5) Structural characterization of molecular motions in NADPH-dependant cytochrome P450 oxidoreductase (Kim) and (6) Substrate binding geometries in Fell dependent non-heme oxygenases from paramagnetic relaxation and heteronudear correlation (Moran). The spectrometer is the center-piece of the "Chemical Proteomics Facility at Marquette", and accordingly has the strong support of Marquette University which has committed the additional $368,945 needed beyond the $500,000 being requested, as well as needed space, facilities, staff, cryogens, warranties and other support. Although neighboring NMR facilities are currently being used, they cannot meet existing demand due largely to the need for travel of > 100 miles and advance scheduling for routine high-field experiments. Such an instrument would therefore accelerate already funded (predominantly NIH) projects across departments and institutions, as well as extend their scope. It will also better leverage the use of regional facilities for follow-up refinement studies, rather than routine early-stage experiments.